Any harm in filling with 91 gas?

It's fine ...
.

 

+1

Putting higher octane fuel in the car will not help the car, but it will not hurt it either.

 

Higher octane=more resistant to detonation/preignition
more resistant to detonation due to having slower flame front propagation
slower flame front propagation actually = potentially less power (oddly enough), unless the car is designed for higher octanes (ie..higher compression, timing, etc)

Will it hurt anything to use a higher octane than recommended by manufacturer? Only your wallet in most circumstances, but not yours this time.

 

It's funny how the various octanes are equally available, but the cars where higher octane is spec'd are few and far between.

https://www.cbc.ca/marketplace/episodes/2012-2013/pump-fiction

Still, to the OP's question: really no harm in it, but no advantage.

 

If it helps carry this thread evem more ad nauseam;

the only thing I can imagine adding is this - ever since 2007, many cars began having the ability to alter timing to allow for higher & lower octane. We had the hybrid Lexus SUV in 2006 and it had this feature which allowed us to use any grade. Yes there would be minuscule loss of efficiency with low-grade, but it still ran FINE -
FINE ... see post #2

.

 

I would be more concern with Costco brand! Who knows what rebranded brand it is and what additive is added if any to keep the engine clean!

 

that's what Chevron wants you to believe.
7 things to know before you buy gas at Costco Wholesale - Clark Howard

.

 

regular price ($3.80).

Now I feel bad. I was just complaining to the wife yesterday about how the price of gas has gone up so much recently.
$2.54...............
Guess I'll stop complaining..

 

We're currently at $1.70 (CDN) per liter. Doing the math, around $4.80 US per (US) gallon. It is pretty much an all-time high I think, hopefully will subside soon.

 

Yeah...but you guys up there are, like, saving the whole planet----right?

 

Just because it’s Top Teir per government regulations does not mean it has enough additives needed to really keep an engine clean. 8 of the top Automakers stated that most Top Tier Gas meets government standards but not theirs. Chevron is one of the best fuels one can buy.

 

We are over $5.00 in Los Angeles

 

FML!

 

So who is selling gasoline that doesn't meet government standards? And why haven't they been shut down and penalized?

 

Dropped a dime a liter, across town, now $1.60 (CDN). All boats going up and down with the tide...

 

Our tide is only rising right now:

... while at least one of your localities seems to have a 'pulse and glide' pattern:


That pattern isn't BC-wide. Victoria has a 'pulse then hang tight' pattern, while Vancouver and BC overall are messier.

 

They do meet government standards, which is a minimum amount of additives to meet the standards. Where some brands (Chevron) exceed the minimum standards.

 

Then just what did you mean by "most Top Tier Gas meets government standards" back at post #13? And why would 'Top Tier' even exist if it was not higher than government standards?